Polarization inverted GaN/GaN junctions fabricated by surface-activated bonding

Abstract

We fabricate polarization-inverted GaN/GaN junctions by directly bonding freestanding GaN (0001) substrates to each other. The conventional surface activated bonding process is used. A ~1-nm defect layer is observed at the as-bonded Ga-face/Ga-face interface using transmission electron microscopy.